DVB-S2 scan succeeds, channels save to DB correctly, but playback fails

[Nzbaxterman]

DVB-S2 scan succeeds, channels save to DB correctly, but playback fails — adapter0-DVB-S-channels.conf is never created.

NextPVR 7.1.1.260616, Ubuntu 25 (native install via nextpvr-helper.deb), tuner is a Hauppauge WinTV-Starburst2 (Montage M88RS6000 demod, cx23885 driver) — confirmed working via

Code:

dvbv5-zap

outside NextPVR (locks cleanly, correct signal/CN).
Channel scan (Single Satellite, custom Optus-D1-160.0E scan file) completes successfully — 21 channels appear correctly in the UI and in

Code:

npvr.db3

(

Code:

CHANNEL_MAPPING.tuning

is populated with correct DVB-S2 tuning XML for each channel).
Playback always fails with "No tuner was available for the requested channel."

Code:

device-adapter0.log

shows the actual cause:

Code:

[ERROR] Failed to get tuning params for (ChannelName) from /var/opt/nextpvr/adapter0-DVB-S-channels.conf

That file is never present on disk — confirmed via

Code:

find / -iname "*channels.conf"

after multiple fresh scans. The scan log shows a temporary

Code:

adapter0-DVB-S-channels-scan.conf

is used during scanning:

Code:

GOT: Channel config will be saved to /var/opt/nextpvr/adapter0-DVB-S-channels-scan.conf

but the final non-

Code:

-scan

file that

Code:

DeviceHostLinux

reads at stream-start time is never written by the save step.
Logs attached (Settings → About → Log Files).

[mvallevand]

What happened a month ago when you original scanned? Did you change tuners?

Martin

[Nzbaxterman]

Bit of a saga, as these things are.

I've only been using NextPVR for FTA channels in NZ using Matt Huisman's IPTV plugin - until TVNZ broke this last month.
But previously the box has 2x TT1300 DVB-S cards in it, which I used in VDR for years.
When I installed NextPVR it just picked up those DVB-S cards.

So I replaced both cards (yesterday) with a DVB-S2 card and replaced the broken LNB on my dish.

So this is the first time I've tried getting this working, with NextPVR and DVB-S2.

[Nzbaxterman]

Double-checked the hardware, and it's working fine. This looks like a similar bug to the one described in "adapter0-DVB-T-channels.conf not saved" . Same symptom, just DVB-S instead of DVB-T: the scan completes and channels save correctly to the database, but the final channels.conf file that DeviceHostLinux needs at stream-start is never written.

Confirmed via dvbv5-zap outside NextPVR: clean lock (C/N 10.79dB, postBER 3.82×10⁻⁶) and a valid 21-second multi-program recording containing all six TVNZ services (TVNZ 1/2/1+1/2+1/DUKE/DUKE+1) with correct H.264 video (1080p/576i) and AAC audio. Proves dish/LNB/cable/tuner/driver/DVB-S2 demod all working correctly, independent of NextPVR.

Input #0, mpegts, from 'tvnz-proof.ts':
Duration: 00:00:20.91, start: 77062.313900, bitrate: 33375 kb/s
Program 1035
Metadata:
service_name : TVNZ 1
service_provider: TVNZ
Stream #0:1: Video: h264 (High), yuv420p, 1920x1080, 25 fps
Stream #0:3(eng): Audio: aac_latm (HE-AAC), 48000 Hz, stereo
Program 1036
Metadata:
service_name : TVNZ 2
Program 1037
Metadata:
service_name : TVNZ 1 +1
Program 1038
Metadata:
service_name : TVNZ 2 +1
Program 1904
Metadata:
service_name : TVNZ DUKE

[mvallevand]

I think it somehow relates to tuner change but could you run

Code:

sudo -u nextpvr LD_LIBRARY_PATH=/opt/nextpvr/system/DeviceHost/x64 /opt/sys/nextpvr/DeviceHost/x64/DeviceHostLinux -device:adapter0/frontend0 -type:DVB-S -parent:0 -scan:/usr/share/dvb/dvb-s/Optus-D1-160.0E

To see if it creates /var/opt/nextpvr/adapter0-DVB-S-channels-scan.conf or maybe an error displays.

Martin

[Nzbaxterman]

This resulted in:

2026-08-21 12:13:07:552 [DEBUG] >>> Scanning@about to store
2026-08-21 12:13:07:553 [DEBUG] header 3
2026-08-21 12:13:07:553 [DEBUG] ~1197:3:169~Ad Tracks~Ad Track~2~11830000HORIZONTAL (encrypted)
2026-08-21 12:13:07:553 [DEBUG] ~1212:3:169~Al Jazeera~SkyNZ~22~11830000HORIZONTAL
2026-08-21 12:13:07:553 [DEBUG] ~1510:3:169~Bravo PLUS1~SkyNZ~22~11830000HORIZONTAL
malloc(): corrupted top size
Aborted
vdruser@Ubuntu-2025:~$


Full log attached.

[Nzbaxterman]

Logs

[mvallevand]

Did you manually update the conf file to add recent frequencies since I know there where recent changes? Maybe there is something at the end tricking our scanner

Martin

[Nzbaxterman]

Yes. I manually edited /usr/share/dvb/dvb-s/Optus-D1-160.0E, since it only had old pre-migration entries (Freeview NZ moved to KoreaSat 6 in April 2025, same 160°E slot, but new frequencies). I updated the stale TVNZ block and appended two new DVBS2 entries for the other current transponders - one for Kordia (Three/Bravo/Eden etc.) and one for Sky (Sky Open/Al Jazeera).

I did wonder if my appended entries were the trigger, so I tested: added a ROLLOFF field to match the others (my Sky entry was missing it) and reran. Crashed at the exact same point, byte-for-byte identical:

~1197:3:169~Ad Tracks~Ad Track~2~11830000HORIZONTAL (encrypted)
~1212:3:169~Al Jazeera~SkyNZ~22~11830000HORIZONTAL
~1510:3:169~Bravo PLUS1~SkyNZ~22~11830000HORIZONTAL
malloc(): corrupted top size
Aborted

So it's not a formatting issue in my file entry. My transponder config itself parses and tunes fine (locks cleanly at 10.41dB C/N, starts storing services correctly). It dies specifically after storing these same 3 channels from this one transponder (real freq 12530MHz), every time. Could be something in the actual broadcast SDT content for this transponder? e.g. the "Ad Tracks" service is flagged encrypted/type 2 (radio-ish), maybe something after Bravo PLUS1 in the service list. Happy to run with more verbose logging or grab a core dump if that'd help you narrow it down.

[mvallevand]

I was thinking more like an extra linefeed or something at the end.

If you remove the 11830 block that what would let us know more if it is sdt related. If that scans than a one minute fill mux for 11830 with dvbv5-zap on an external link would help.

Martin